/*
 * Copyright (c) 2001-2009 Caucho Technology, Inc.  All rights reserved.
 *
 * The Apache Software License, Version 1.1
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Caucho Technology (http://www.caucho.com/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "Hessian", "Resin", and "Caucho" must not be used to
 *    endorse or promote products derived from this software without prior
 *    written permission. For written permission, please contact
 *    info@caucho.com.
 *
 * 5. Products derived from this software may not be called "Resin"
 *    nor may "Resin" appear in their names without prior written
 *    permission of Caucho Technology.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL CAUCHO TECHNOLOGY OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @author Scott Ferguson
 */

package com.caucho.hessian.server;

import com.caucho.hessian.io.AbstractHessianInput;
import com.caucho.hessian.io.AbstractHessianOutput;
import com.caucho.hessian.io.Hessian2Input;
import com.caucho.hessian.io.Hessian2Output;
import com.caucho.hessian.io.HessianFactory;
import com.caucho.hessian.io.HessianInput;
import com.caucho.hessian.io.HessianOutput;
import com.caucho.hessian.io.HessianDebugInputStream;
import com.caucho.hessian.io.HessianDebugOutputStream;
import com.caucho.hessian.io.HessianInputFactory;
import com.caucho.hessian.io.SerializerFactory;
import com.caucho.services.server.AbstractSkeleton;
import com.caucho.services.server.ServiceContext;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.Writer;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Proxy class for Hessian services.
 */
public class HessianSkeleton extends AbstractSkeleton {
    private static final Logger log = Logger.getLogger(HessianSkeleton.class.getName());

    private boolean _isDebug;

    private HessianInputFactory _inputFactory = new HessianInputFactory();
    private HessianFactory _hessianFactory = new HessianFactory();

    private Object _service;

    /**
     * Create a new hessian skeleton.
     *
     * @param service the underlying service object.
     * @param apiClass the API interface
     */
    public HessianSkeleton(Object service, Class apiClass) {
        super(apiClass);

        if (service == null)
            service = this;

        _service = service;

        if (!apiClass.isAssignableFrom(service.getClass()))
            throw new IllegalArgumentException("Service " + service + " must be an instance of " + apiClass.getName());
    }

    /**
     * Create a new hessian skeleton.
     *
     * @param service the underlying service object.
     * @param apiClass the API interface
     */
    public HessianSkeleton(Class apiClass) {
        super(apiClass);
    }

    public void setDebug(boolean isDebug) {
        _isDebug = isDebug;
    }

    public boolean isDebug() {
        return _isDebug;
    }

    public void setHessianFactory(HessianFactory factory) {
        _hessianFactory = factory;
    }

    /**
     * Invoke the object with the request from the input stream.
     *
     * @param in the Hessian input stream
     * @param out the Hessian output stream
     */
    public void invoke(InputStream is, OutputStream os) throws Exception {
        invoke(is, os, null);
    }

    /**
     * Invoke the object with the request from the input stream.
     *
     * @param in the Hessian input stream
     * @param out the Hessian output stream
     */
    public void invoke(InputStream is, OutputStream os, SerializerFactory serializerFactory) throws Exception {
        boolean isDebug = false;

        if (isDebugInvoke()) {
            isDebug = true;

            PrintWriter dbg = createDebugPrintWriter();
            HessianDebugInputStream dIs = new HessianDebugInputStream(is, dbg);
            dIs.startTop2();
            is = dIs;
            HessianDebugOutputStream dOs = new HessianDebugOutputStream(os, dbg);
            dOs.startTop2();
            os = dOs;
        }

        HessianInputFactory.HeaderType header = _inputFactory.readHeader(is);

        AbstractHessianInput in;
        AbstractHessianOutput out;

        switch (header) {
            case CALL_1_REPLY_1:
                in = _hessianFactory.createHessianInput(is);
                out = _hessianFactory.createHessianOutput(os);
                break;

            case CALL_1_REPLY_2:
                in = _hessianFactory.createHessianInput(is);
                out = _hessianFactory.createHessian2Output(os);
                break;

            case HESSIAN_2:
                in = _hessianFactory.createHessian2Input(is);
                in.readCall();
                out = _hessianFactory.createHessian2Output(os);
                break;

            default:
                throw new IllegalStateException(header + " is an unknown Hessian call");
        }

        if (serializerFactory != null) {
            in.setSerializerFactory(serializerFactory);
            out.setSerializerFactory(serializerFactory);
        }

        try {
            invoke(_service, in, out);
        } finally {
            in.close();
            out.close();

            if (isDebug)
                os.close();
        }
    }

    /**
     * Invoke the object with the request from the input stream.
     *
     * @param in the Hessian input stream
     * @param out the Hessian output stream
     */
    public void invoke(AbstractHessianInput in, AbstractHessianOutput out) throws Exception {
        invoke(_service, in, out);
    }

    /**
     * Invoke the object with the request from the input stream.
     *
     * @param in the Hessian input stream
     * @param out the Hessian output stream
     */
    public void invoke(Object service, AbstractHessianInput in, AbstractHessianOutput out) throws Exception {
        ServiceContext context = ServiceContext.getContext();

        // backward compatibility for some frameworks that don't read
        // the call type first
        in.skipOptionalCall();

        // Hessian 1.0 backward compatibility
        String header;
        while ((header = in.readHeader()) != null) {
            Object value = in.readObject();

            context.addHeader(header, value);
        }

        String methodName = in.readMethod();
        int argLength = in.readMethodArgLength();

        Method method;

        method = getMethod(methodName + "__" + argLength);

        if (method == null)
            method = getMethod(methodName);

        if (method != null) {
        } else if ("_hessian_getAttribute".equals(methodName)) {
            String attrName = in.readString();
            in.completeCall();

            String value = null;

            if ("java.api.class".equals(attrName))
                value = getAPIClassName();
            else if ("java.home.class".equals(attrName))
                value = getHomeClassName();
            else if ("java.object.class".equals(attrName))
                value = getObjectClassName();

            out.writeReply(value);
            out.close();
            return;
        } else if (method == null) {
            out.writeFault("NoSuchMethodException", "The service has no method named: " + in.getMethod(), null);
            out.close();
            return;
        }

        Class<?>[] args = method.getParameterTypes();

        if (argLength != args.length && argLength >= 0) {
            out.writeFault("NoSuchMethod", "method " + method + " argument length mismatch, received length=" + argLength, null);
            out.close();
            return;
        }

        Object[] values = new Object[args.length];

        for (int i = 0; i < args.length; i++) {
            // XXX: needs Marshal object
            values[i] = in.readObject(args[i]);
        }

        Object result = null;

        try {
            result = method.invoke(service, values);
        } catch (Exception e) {
            Throwable e1 = e;
            if (e1 instanceof InvocationTargetException)
                e1 = ((InvocationTargetException) e).getTargetException();

            log.log(Level.FINE, this + " " + e1.toString(), e1);

            out.writeFault("ServiceException", e1.getMessage(), e1);
            out.close();
            return;
        }

        // The complete call needs to be after the invoke to handle a
        // trailing InputStream
        in.completeCall();

        out.writeReply(result);

        out.close();
    }

    protected boolean isDebugInvoke() {
        return (log.isLoggable(Level.FINEST) || isDebug() && log.isLoggable(Level.FINE));
    }

    /**
     * Creates the PrintWriter for debug output. The default is to
     * write to java.util.Logging.
     */
    protected PrintWriter createDebugPrintWriter() throws IOException {
        return new PrintWriter(new LogWriter(log));
    }

    static class LogWriter extends Writer {
        private Logger _log;
        private StringBuilder _sb = new StringBuilder();

        LogWriter(Logger log) {
            _log = log;
        }

        public void write(char ch) {
            if (ch == '\n' && _sb.length() > 0) {
                _log.fine(_sb.toString());
                _sb.setLength(0);
            } else
                _sb.append((char) ch);
        }

        public void write(char[] buffer, int offset, int length) {
            for (int i = 0; i < length; i++) {
                char ch = buffer[offset + i];

                if (ch == '\n' && _sb.length() > 0) {
                    _log.fine(_sb.toString());
                    _sb.setLength(0);
                } else
                    _sb.append((char) ch);
            }
        }

        public void flush() {
        }

        public void close() {
        }
    }
}
